1. Field of the Invention
This invention relates to an automatic copying method and apparatus. More particularly, it relates to a copying machine having an electronic sorter function. See U.S. Pat. Nos. 4,054,380 and 3,829,083.
Along with the recent tendency of copying machines toward compactness, high speed and multi-function, automatic document treating devices have come into wide use which not only enable production of the same copies of an original document but also have the automatic book-binding function such as automatic document feeder (hereinafter referred to as (ADF) and automatic page arrangement (hereinafter referred to as sorter).
2. Description of the Prior Art
Most of the conventional copying machines are of the type as shown in FIGS. 1 and 2 of the accompanying drawings in which an electrophotographic copying machine 8 is additionally provided with an ADF mechanism.
Briefly describing FIG. 1, a lowermost one of sheet originals is fed from a tray 2 containing therein a stock of sheet originals 1 by a roller 3 through a transport belt 4 onto an original carriage 5. After the fed original is fixedly set on the original carriage, the copying operation is effected through the well-known process of the electrophotographic copying machine wherein the optical system is reciprocated and the original is subjected to the slit exposure. After the completion of the copying, the original is transported by the now reversely moving transport belt 4 and dischargedinto a discharge tray 7 by a pawl 6. Thereafter, by repeating the same operation, a volume of printed matters having pages arranged in good order may be automatically prepared. However, in order to prepare a second volume of copies, the originals in the tray 7 must be manually returned into the tray 2 and this means complexity of handling of the originals and moreover, the operator must stay with the copying machine throughout the copying operation.
In the apparatus of FIG. 2, the lowermost one of the sheet originals is fed from a tray 8 to a first transport roller 10 by a roller 9 and transported onto an original carriage by rollers 11 and 12 and fixedly set thereon. The copying operation is effected with that original being illuminated. After the completion of the copying, the roller 12 is operated to discharge the original from the original carriage, and the original is again set in the tray 8 by a roller 13. By repeating the same operation, a plurality of volumes of printed matters having pages well arranged are prepared.
However, where the number of volumes to be bound is great, the frequency with which the originals are set on the original carriage and discharged therefrom is also great and so, there are dangers of the precious originals being injured. There are also dangers that the originals are transported in overlapped condition and accordingly, a volume of copies having missing pages may be prepared.
There is another system whereby a necessary number of copies are obtained from one original and those copies are sorted into a necessary number of volumes by a sorter and such operation is repeated by replacing the original with new ones in succession. This system eliminates the need to set the original often and reduces the danger of injuring the originals, but where a great number of volumes are to be bound, the sorter must be on a large scale and this means an increased mechanical space for temporarily storing the copies and moreover, a complicated sorting function.
When considering the operability, the former automatic document feeding system is restricted to sheet originals and cannot use book-type originals. On the other hand, in the latter sorter system, the operator must be attendant on the machine while turning the pages until the book binding is completed. This means waste of much time and labor to the operator.
Also, where the ADF is used, in order to enable only a desired one of multiple document originals to be copied, it has been necessary for the operator to be attendant on the machine at all times and to take that one original from among the multiple originals and have it copied. An attempt to automate this would possibly require a very huge system.
Still more, it has been very difficult to copy a desired number of non-adjacent documents in a desired order.